One of this year's most anticipated car computer games – Gran Turismo 4 – has been delayed while its makers put the finishing touches on technology to enable it to be played online.

Turismo's five-track teaser

One of this year's most anticipated car computer games -- Gran Turismo 4 -- has been delayed while its makers put the finishing touches on technology to enable it to be played online.

Polyphony Digital in Japan, which writes the Gran Turismo software for Sony Computer Entertainment, aims eventually to have six players anywhere on the globe able to race each other over the internet.

Sony Computer Entertainment meanwhile is releasing a teaser version, Gran Turismo 4: Prologue Signature Edition. Far from the 500 cars and 100-plus race circuits in the full version, Prologue has five tracks and 50 cars in which to complete licence tests.

The package includes a behind-the-scenes Making of GT4 DVD movie prepared by the producers of BBC TV's Top Gear.

It is unclear whether the teaser game is a marketing ploy or a genuine attempt to keep fans happy. GT4: Prologue is due in Australia on May 28 for $59.95 but Sony will not speculate on when the complete version will go on sale.

Gran Turismo is one of Australia's biggest selling games -- more than 1 million copies have been sold in the past seven years.